STAMFORD, Conn. — Clean Diesel Technologies says a study has shown that its Platinum Plus DFX fuel additive for heavy-trucks boosts fuel economy by anywhere from four-to-12 per cent.

The study was conducted on a fleet of heavy-duty trucks traveling over commercial roadways, explains Clean Diesel. It adds the fuel economy figures are based on fleet averages.

More than 200 trucks took part in the tests, which extended to more than 8 million miles of commercial highway service.

The highest percentage of improvement was found in local delivery fleets with stop-and-go service, as high as 12 per cent in several cases.

Over-the-road, long-haul fleets, or those with mixed service, were generally in the four-to-seven per cent range. A total of seven separate fleets were involved in the field demonstrations conducted over the last 18 months.